Lighting fixtures
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- KOITO MFG CO LTD
- Filing Date
- 2022-10-05
- Publication Date
- 2026-06-16
Smart Images
Figure 0007874653000001 
Figure 0007874653000002 
Figure 0007874653000003
Abstract
Description
Technical Field
[0001] The present invention relates to a lighting fixture.
Background Art
[0002] A lighting fixture for cooling a light source is known, and such a lighting fixture is disclosed in Patent Document 1 below. The lighting fixture of Patent Document 1 includes a substrate on which a light source is mounted, a heat sink on which the substrate is disposed, and a fan that blows air to the heat sink to cool the heat sink. Heat generated by the light source is transmitted to the heat sink through the substrate and released from the heat sink. Thereby, the light source is cooled.
[0003]
Patent Document 1
Summary of the Invention
[0004] In a lighting fixture, the light source is cooled by heat radiation from the heat sink as described above, but there is a desire to improve the cooling efficiency of the light source.
[0005] Therefore, an object of the present invention is to provide a lighting fixture capable of improving the cooling efficiency of a light source.
[0006] To achieve the above objective, a light fixture according to a first aspect of the present invention comprises a substrate on which a light source is mounted, a base plate on which the substrate is arranged, a plurality of heat dissipation fins arranged in parallel at intervals from each other on the back surface of the base plate opposite to the substrate side, and a heat sink including mounting bosses provided on the back surface, an impeller provided on the side of the plurality of heat dissipation fins opposite to the base plate and rotating along the back surface to send air into the gaps between adjacent heat dissipation fins, and a fan provided to the side of the impeller and including a support member that supports the impeller and is attached to the mounting boss, wherein at least a portion of the mounting boss is provided in the rear region in the direction of rotation of the impeller among four regions formed by a first reference line that passes through the rotation axis of the impeller and extends in the direction of extension of the heat dissipation fins and a second reference line that passes through the rotation axis and extends in a direction perpendicular to the first reference line when the fan is viewed from the rear.
[0007] In the above configuration, the air blown from the impeller into the gaps between adjacent heat sink fins hits the back surface of the base plate and flows through the gaps along the heat sink fins. Most of the air flowing through the gaps tends to flow towards one end of the gap due to the vortex in the airflow caused by the rotation of the impeller. In the above configuration, at least a portion of the mounting boss is located in the rear region in the direction of rotation of the impeller between adjacent regions in the extending direction of the four regions when the fan is viewed from the rear. Furthermore, since a support member is attached to the mounting boss, the mounting boss is located to the side of the impeller in the rear region when the fan is viewed from the rear, in a position that does not obstruct the airflow. When the mounting boss is located in this way, it is less likely to obstruct the airflow compared to when the mounting boss is located in the front region in the direction of rotation of the impeller between adjacent regions in the extending direction of the heat sink fins. As a result, the airflow is more likely to flow and blow out to the sides of the heat sink fins, making it easier to cool the heat sink fins. Therefore, according to the above configuration, the heat generated by the light source can be easily transferred to the heat dissipation fins, thereby improving the cooling efficiency of the light source.
[0008] Furthermore, in order to achieve the above objective, a lighting fixture according to a second aspect of the present invention comprises a substrate on which a light source is mounted, a base plate on which the substrate is arranged, a heat sink including a plurality of heat dissipation fins arranged in parallel at intervals from each other on the back surface of the base plate opposite to the substrate side, a fan provided on the side of the plurality of heat dissipation fins opposite to the base plate and rotating along the back surface to send air into the gaps between adjacent heat dissipation fins, and a structure other than the heat sink and the fan arranged on the back surface side of the base plate, wherein the structure is located in a region other than downwind of the air that passes through the gaps in the direction in which the heat dissipation fins extend.
[0009] The air blown from the fan into the gaps between adjacent heat sink fins hits the back surface of the base plate and flows along the heat sink fins through the gaps. When viewing the fan from the rear, most of the air flowing through the gaps tends to flow towards one end of the gap due to the vortex created by the fan's rotation. However, in the above configuration, the structure is located in a region other than the leeward direction of the air passing through the gaps in the direction of the heat sink fins. As a result, compared to the case where the structure is located in the leeward direction of the air passing through the gaps, the structure is less likely to obstruct the air passing through the gaps, the air is more likely to blow out to the side of the heat sink fins, and the heat sink fins can be cooled more easily. Therefore, according to the above configuration, heat generated by the light source can be more easily transferred to the heat sink fins, and the cooling efficiency of the light source can be improved.
[0010] Furthermore, in the lighting fixture according to the second embodiment, the structure may be positioned away from the heat dissipation fins.
[0011] According to the above configuration, compared to the case where the structure is placed in contact with the heat dissipation fins, heat from the heat dissipation fins may be less likely to be transferred to the structure, and deformation of the structure due to such heat may be suppressed.
[0012] Furthermore, in the lighting fixture according to the second embodiment, the structure may include a conductive member that supplies power to the fan.
[0013] Furthermore, in the lighting fixture according to the second embodiment, the light source overlaps with at least a portion of a predetermined region between a first reference line extending in the direction of extension through the rotation axis of the fan and the heat dissipation fin furthest from the first reference line among the plurality of heat dissipation fins when the fan is viewed from the rear, and the predetermined region may overlap with the region on the front side in the direction of rotation of the fan among four regions formed by the first reference line and a second reference line extending in a direction perpendicular to the first reference line through the rotation axis, where adjacent regions in the direction of extension are located.
[0014] Furthermore, in the lighting fixture according to the second embodiment, the heat sink further includes a mounting boss provided on the back surface, and the fan includes an impeller and a support member provided to the side of the impeller, supporting the impeller and attached to the mounting boss, and at least a portion of the mounting boss may be provided in the rear region in the direction of rotation of the impeller among four regions formed by a first reference line passing through the rotation axis of the impeller and extending in the extending direction and a second reference line passing through the rotation axis and extending in a direction perpendicular to the first reference line, where adjacent regions in the extending direction are located.
[0015] In the above configuration, a support member is attached to the mounting boss, so when viewing the fan from the rear, the mounting boss is located to the side of the impeller in the rear region, in a position that does not obstruct the airflow. When the mounting boss is located in this way, it is less likely to obstruct the airflow compared to when the mounting boss is located in the region in front of the impeller's rotation direction, between adjacent regions in the direction of the heat dissipation fins' extension. As a result, the airflow is more likely to flow and blow out to the side of the heat dissipation fins, making it easier to cool the heat dissipation fins. Therefore, according to the above configuration, heat generated by the light source can be easily transferred to the heat dissipation fins, and the cooling efficiency of the light source can be improved.
[0016] Furthermore, in the lamps according to the first and second embodiments, at least a portion of the mounting boss may be provided in each of the rear regions of the impeller in the direction of rotation between adjacent regions in the extending direction among the four regions.
[0017] With the above configuration, since the fan is attached to the heatsink at two points, the fan's oscillation due to the rotation of the impeller can be suppressed compared to when it is attached to the heatsink at one point. When the fan's oscillation is suppressed, it becomes easier for air from the impeller to flow into the gaps, and the heat sink fins can be cooled more easily compared to when the fan's oscillation is not suppressed.
[0018] Furthermore, in the luminaires according to the first and second embodiments, one of the mounting bosses does not need to overlap the other mounting boss along the extending direction.
[0019] With the above configuration, compared to the case where one mounting boss overlaps the other mounting boss along the extending direction, air can flow more easily and blow out to the side of the heat dissipation fins, making it easier to cool the heat dissipation fins. Therefore, heat generated by the light source can be more easily transferred to the heat dissipation fins, improving the cooling efficiency of the light source.
[0020] Alternatively, in the luminaire according to the first and second embodiments, one of the mounting bosses may overlap at least a portion of the other mounting boss along the extending direction.
[0021] Furthermore, in the lighting fixture according to the first and second embodiments, when the fan is viewed from the rear, the light source overlaps with at least a portion of a predetermined area between the first reference line and the heat dissipation fin that is furthest from the first reference line among the plurality of heat dissipation fins, and the predetermined area may overlap with the area on the front side in the direction of rotation of the impeller between adjacent areas in the extending direction.
[0022] As described above, most of the wind flowing through the gap flows toward the edge of the gap overlapping the front region in the rotation direction of the impeller. Therefore, in the heat sink, a predetermined region between the first reference line and the heat dissipation fin farthest from the first reference line in the front region is more easily cooled than the region outside the predetermined region. According to the above configuration, compared with the case where the light source overlaps the outside region, the heat generated by the light source can be more easily transmitted to the heat dissipation fin, and the cooling efficiency of the light source can be improved.
[0023] As described above, according to the present invention, a lighting fixture capable of improving the cooling efficiency of a light source can be provided.
Brief Description of Drawings
[0024] [Figure 1] It is a diagram schematically showing a lighting fixture in an embodiment of the present invention. [Figure 2] It is an exploded perspective view of the lighting unit seen from obliquely above in the front. [Figure 3] It is an exploded perspective view of the lighting unit seen from obliquely below in the rear. [Figure 4] It is a vertical sectional view of the lighting unit. [Figure 5] It is a perspective view of the heat sink seen from obliquely above in the front. [Figure 6] It is a front view schematically showing a substrate. [Figure 7] It is a front view of the state where the reflector unit is attached to the heat sink seen from the front side. [Figure 8] It is a diagram showing an enlarged view of a part including a light distribution forming part in FIG. 7. [Figure 9] It is a diagram showing an enlarged view of a part including a light distribution forming part in FIG. 4. [Figure 10] It is a rear view of the heat sink. [Figure 11] It is a diagram showing an enlarged view of a part of FIG. 4 and schematically showing an optical path example of light emitted from a first light source and light emitted from a second light source. [[ID=Q3]] [Figure 12] It is a diagram showing a light distribution pattern of a low beam in the present embodiment. [Figure 13]This figure shows the light distribution pattern of the high beam in this embodiment. [Figure 14] This is a rear view of the heatsink in a modified example. [Modes for carrying out the invention]
[0025] The following examples illustrate embodiments of the lighting fixture according to the present invention, along with the accompanying drawings. The embodiments illustrated below are provided to facilitate understanding of the present invention and are not intended to limit its interpretation. The present invention can be modified and improved without departing from its spirit. Furthermore, the components of each embodiment illustrated below may be combined as appropriate. Note that in the drawings referenced below, the dimensions of each component may be shown differently for the sake of clarity.
[0026] Figure 1 is a schematic diagram of the lamp in this embodiment, and is a schematic diagram of the vertical cross-section of the lamp. The lamp in this embodiment is a vehicle headlight, and is for automobiles. Vehicle headlights are generally installed on the left and right sides of the front of the vehicle. In this specification, "right" means the right side in the direction of travel of the vehicle, and "left" means the left side in the direction of travel of the vehicle. The left and right vehicle headlights have the same configuration, except that their shape is generally symmetrical in the left-right direction. For this reason, one of the vehicle headlights will be described below.
[0027] As shown in Figure 1, the vehicle headlight 1 of this embodiment mainly comprises a housing 10 and a lighting unit LU. Figure 1 is a side view of the vehicle headlight 1, and for ease of understanding, the housing 10 is shown in cross-section in Figure 1.
[0028] The housing 10 includes a lamp housing 11 and a light-transmitting front cover 12. The front of the lamp housing 11 is open, and the front cover 12 is fixed to the lamp housing 11 so as to close this opening. The space formed by the lamp housing 11 and the front cover 12 is a luminaire chamber R, and a luminaire unit LU is housed in this luminaire chamber R.
[0029] Figure 2 is an exploded perspective view of the luminaire unit LU viewed from the front and diagonally above. Figure 3 is an exploded perspective view of the luminaire unit LU viewed from the rear and diagonally below. Figure 4 is a vertical cross-sectional view of the luminaire unit LU. As shown in Figures 1 to 4, the luminaire unit LU of this embodiment mainly comprises a heat sink 20, an axial flow fan 30, a circuit board 40, a reflector unit 50, a projection lens 60, and a holder 70. Note that Figure 4 is a vertical cross-sectional view of the luminaire unit LU along the optical axis of the projection lens 60, which will be described later, and the fan 30 is omitted from the description in Figure 4.
[0030] Figure 5 is a perspective view of the heat sink 20 from the front and diagonally above. The heat sink 20 is made of a material with excellent heat dissipation properties, such as metal. As shown in Figures 2 to 5, the heat sink 20 of this embodiment mainly comprises a base plate 21 on which the substrate 40 is placed, a plurality of heat dissipation fins 22, a plurality of mounting bosses 23a, 23b, and a peripheral wall portion 24.
[0031] The base plate 21 is a plate-shaped member with its front surface facing forward and its back surface facing backward, and has an inclined portion 25 that slopes upward and backward. A pedestal 25a is provided on the inclined portion 25 that protrudes forward, and the end face 25s of the pedestal 25a is a flat surface that slopes upward and backward. The substrate 40 is placed on this end face 25s. Projections 26 that protrude forward are provided on both the left and right sides of the pedestal 25a. In addition, pins 27 that protrude forward are provided on the right and left sides of the pedestal 25a on the base plate 21.
[0032] Multiple heat dissipation fins 22, mounting bosses 23a, 23b, and peripheral wall portions 24 are located on the back surface of the base plate 21 opposite to the substrate 40 side, extending towards the rear and formed integrally with the base plate 21. The fan 30 is located behind the multiple heat dissipation fins 22 and fixed to the mounting bosses 23a, 23b. The heat sink 20 is cooled by airflow from the fan 30. The back surface of the heat sink 20, where the multiple heat dissipation fins 22, mounting bosses 23a, 23b, peripheral wall portions 24, and fan 30 are located, will be described later.
[0033] The substrate 40 is a flat plate-shaped member made of, for example, metal, and as described above, is placed on the end face 25s of the base 25a of the heat sink 20. Figure 6 is a schematic front view of the substrate 40. As shown in Figure 6, in this embodiment, the outer shape of the substrate 40 is a roughly symmetrical rectangular shape, and the substrate 40 has a pair of recesses 45 in which the left and right sides 40sf, which face each other, are recessed. The recesses 45 are roughly rectangular in shape. The sides 40sf of the substrate 40 that define the recesses 45 include a pair of straight portions 45S that extend in the left-right direction and face each other, a bottom portion 45B that is the tip in the recess direction and extends in the vertical direction, and a corner portion 45R that connects the straight portions 45S and the bottom portion 45B. The projections 26 of the heat sink 20 are inserted into each recess 45. The projections 26 are shown in Figure 6. The pair of straight sections 45S in the recess 45 and the outer circumferential surface of the projection 26 restrict the vertical movement of the substrate 40 along the end face 25s. Furthermore, the bottom 45B of one recess 45 and the outer circumferential surface of one projection 26, and the bottom 45B of the other recess 45 and the outer circumferential surface of the other projection 26, restrict the horizontal movement of the substrate 40 along the end face 25s. In this way, the recess 45 and the projection 26 restrict the movement of the substrate 40 along the end face 25s, thereby positioning the substrate 40 relative to the heat sink 20. The shape of the recess 45 is not particularly limited. The projection 26 may also be press-fitted into the recess 45.
[0034] In this embodiment, a first light source 41, a second light source 42, an integrated circuit 43, and a connector 44 are mounted on the front surface 40f of the substrate 40.
[0035] The first light source 41 emits light from a planar emission surface that forms the low beam light distribution pattern. The second light source 42 emits light from a planar emission surface that forms the high beam light distribution pattern together with the light emitted from the first light source 41. In this embodiment, the first light source 41 and the second light source 42 are LED arrays consisting of a plurality of LEDs (Light Emitting Diodes) arranged in the left-right direction, and are positioned inward from the bottom 45B of the recess 45. In this embodiment, the second light source 42 is located below the first light source 41 and overlaps with the recess 45 in the left-right direction, which is the direction in which the plurality of LEDs are arranged.
[0036] The integrated circuit 43 is positioned below the second light source 42, and the connector 44 is positioned below the integrated circuit 43. The substrate 40 is provided with a circuit (not shown) through which the connector 44 is connected to the first light source 41, the connector 44 to the integrated circuit 43, and the integrated circuit 43 to the second light source 42. Power is supplied to the connector 44 from a power supply unit (not shown). As a result, power is supplied from the connector 44 to the first light source 41, and from the connector 44 to the second light source 42 via the integrated circuit 43. The integrated circuit 43 includes multiple switch elements and can individually adjust the power supplied to each LED of the second light source 42. The integrated circuit 43 only needs to be able to adjust the power supplied to at least one of the first light source 41 and the second light source 42, and its configuration is not particularly limited. The arrangement of the integrated circuit 43 and the connector 44 is also not particularly limited. Furthermore, the integrated circuit 43 does not need to be mounted on the substrate 40; in this case, the connector 44 and the second light source 42 are connected by a circuit.
[0037] When the substrate 40 is viewed from the front, the areas on the substrate 40 where the first light source 41, the second light source 42, and the integrated circuit 43 are mounted coincide with the end face 25s. Also, as described above, since the end face 25s is tilted upwards toward the rear, the substrate 40 is tilted similarly, and the front surface 40f of the substrate 40 faces diagonally upwards and forwards. The perpendicular line 41L of the emission surface of the first light source 41 and the perpendicular line 42L of the emission surface of the second light source 42 are approximately perpendicular to the front surface 40f of the substrate 40. For this reason, the perpendicular lines 41L and 42L face diagonally upwards and forwards. The perpendicular lines 41L and 42L shown in Figure 4 are the same as straight lines that pass through the center of the emission surface, are parallel to the emission direction of the light with the strongest intensity emitted from the light source, and pass through the area on the emission surface from which that light is emitted.
[0038] Figure 7 is a front view of the reflector unit 50 attached to the heat sink 20, viewed from the front, and is a view along the optical axis of the projection lens 60, which will be described later. As shown in Figures 4 and 7, the reflector unit 50 is positioned in front of the substrate 40, and the substrate 40 is sandwiched between the reflector unit 50 and the heat sink 20. The reflector unit 50 in this embodiment consists of a light distribution forming section 50a and cover sections 50b connected to both the left and right sides and below the light distribution forming section 50a, and the light distribution forming section 50a and the cover sections 50b are integrally formed. In Figure 7, the light distribution forming section 50a is surrounded by a dashed line. In this embodiment, the reflector unit 50 is fixed to the heat sink 20 by fixing the cover section 50b to the heat sink 20 with screws 80. Examples of materials that make up the reflector unit 50 include plated metal, and the reflector unit 50 is formed, for example, by machining and plating a metal member obtained by casting.
[0039] Figure 8 is a magnified view of the area including the light distribution forming section 50a in Figure 7, and Figure 9 is a magnified view of the area including the light distribution forming section 50a in Figure 4. As shown in Figures 8 and 9, the light distribution forming section 50a of this embodiment mainly consists of a first reflector 51, a pair of second reflectors 52a, 52b, a pair of upper side reflectors 53a, 53b, and a pair of lower side reflectors 54a, 54b.
[0040] The first reflector 51 is positioned between the first light source 41 and the second light source 42 and extends in the front-rear direction. The first reflector 51 has a tapered shape toward its front end 51e, and its upper and lower surfaces are reflective surfaces 51ur and 51dr that reflect light. In this embodiment, the upper reflective surface 51ur is located below the perpendicular line 41L of the first light source 41 and curves downward in a concave shape. The lower reflective surface 51dr is located above the perpendicular line 42L of the second light source 42 and curves upward in a concave shape. Furthermore, the front end 51e of the first reflector 51 has a shape that matches the cutoff line in the low beam light distribution pattern described later, and is gradually concave backward from the left and right ends toward the center. As described above, since the perpendicular line 41L of the first light source 41 and the perpendicular line 42L of the second light source 42 point diagonally upward and forward, the perpendicular line 41L moves away from the first reflector 51 in the forward direction, and the perpendicular line 42L moves closer to the first reflector 51 in the forward direction.
[0041] The second reflector 52a is positioned above the first reflector 51 and has a reflective surface 52ar on the side facing the first reflector 51. In this embodiment, the second reflector 52a is a plate-shaped member, and the side surface of the plate-shaped member is the reflective surface 52ar. This reflective surface 52ar and the reflective surface 51ur on the upper side of the first reflector 51 extend along the parallel direction of the plurality of LEDs constituting the first light source 41, forming a pair of reflectors positioned to sandwich the plurality of LEDs from above and below.
[0042] The other second reflector 52b is positioned below the first reflector 51 and has a reflective surface 52br on the side facing the first reflector 51. In this embodiment, the second reflector 52b is a plate-shaped member, and one of the main surfaces of the plate-shaped member is the reflective surface 52br. This reflective surface 52br and the lower reflective surface 51dr of the first reflector 51 extend along the parallel direction of the plurality of LEDs constituting the second light source 42, forming a pair of reflectors positioned to sandwich the plurality of LEDs from above and below.
[0043] One upper side reflector 53a is formed at one end of the space between the upper reflective surface 51ur of the first reflector 51 and the reflective surface 52ar of one of the second reflectors 52a, in the parallel direction of the multiple LEDs constituting the first light source 41. The other upper side reflector 53b is formed at the other end of the same space. The pair of upper side reflectors 53a and 53b are formed such that the distance between them increases from rear to front. An opening 55 is formed in the light distribution forming section 50a, surrounded by this pair of upper side reflectors 53a and 53b, the first reflector 51, and the second reflector 52a, and the emission surface 41s of the first light source 41 overlaps with the opening 55 in a front view. Note that in Figure 8, for ease of viewing, one first light source 41 and emission surface 41s are labeled with reference numerals, while the reference numerals for the others are omitted.
[0044] One lower side reflector 54a is formed at one end of the space between the lower reflective surface 51dr of the first reflector 51 and the reflective surface 52br of the other second reflector 52b, in the parallel direction of the multiple LEDs constituting the second light source 42. The other lower side reflector 54b is formed at the other end of the same space. The pair of lower side reflectors 54a and 54b are formed such that the distance between them increases from rear to front. An opening 56 is formed in the light distribution forming section 50a, surrounded by this pair of lower side reflectors 54a and 54b, the first reflector 51, and the second reflector 52b, and the emission surface 42s of the second light source 42 overlaps with the opening 56 in a front view. Note that in Figure 8, for ease of viewing, one second light source 42 and emission surface 42s are labeled with reference numerals, while the reference numerals for the others are omitted. Furthermore, the opening 56 and the opening 55 penetrate from a flat opposing surface 50as in the light distribution forming section 50a that is generally parallel to the substrate 40, to the surface opposite to the substrate 40. Note that the opposing surface 50as does not have to be flat.
[0045] As shown in Figure 7, through holes 57 are provided on both the left and right sides of the cover portion 50b of this embodiment, and the pins 27 of the heat sink 20 are inserted into these through holes 57. Therefore, the circumferential surface defining the through holes 57 and the pins 27 allow the reflector unit 50 to be positioned relative to the heat sink 20. Also, as shown in Figure 4, in a direction perpendicular to the front surface 40f of the substrate 40, the cover portion 50b overlaps the integrated circuit 43 and the connector 44. Therefore, when the substrate 40 is viewed from above, the cover portion 50b covers the integrated circuit 43 and the connector 44 mounted on the substrate 40. Furthermore, as shown in Figure 3, the light distribution forming portion 50a and the cover portion 50b are provided with a plurality of ribs 58 that protrude toward the rear. When the reflector unit 50 is fixed to the heat sink 20, the tips of the ribs 58 abut against the front surface 40f of the substrate 40, and the substrate 40 is pressed against the heat sink 20 by the reflector unit 50 and fixed to the heat sink 20.
[0046] In Figure 6, the areas 46a, 46b, 46c, and 46d that the reflector unit 50 presses against the substrate 40 are indicated by hatched lines. In this embodiment, the reflector unit 50 presses against four areas 46a, 46b, 46c, and 46d, with areas 46a and 46b located outside the bottom 45B of one recess 45, and areas 46c and 46d located outside the bottom 45B of the other recess 45. Therefore, the reflector unit 50 presses against the areas on the substrate 40 that are outside the bottom 45B of each recess 45. Furthermore, areas 46a and 46b are located above and below one recess 45, respectively, and sandwich this one recess 45 in a direction along the side surface 40sf. Furthermore, parts 46c and 46d are located above and below the other recess 45, respectively, and sandwich this other recess 45 in a direction along the side surface 40sf. As a result, the reflector unit 50 presses both sides of each recess 45 on the substrate 40. In addition, the outer shape of parts 46a, 46b, 46c, and 46d is generally rectangular, but is not particularly limited.
[0047] The projection lens 60 is a lens that changes the divergence angle of transmitted light and is positioned in front of the reflector unit 50. In this embodiment, the projection lens 60 is a biconvex aspherical lens with an outer shape that is elongated in the left-right direction and is generally oval-track shaped. The outer surface of the projection lens 60 is provided with a flange portion 61 that protrudes outward and extends around the entire circumference. The optical axis 60c of the projection lens 60 extends in the front-rear direction, intersects with the first reflector 51, and passes between the first light source 41 and the second light source 42. The rear focal point 60f of the projection lens 60 is located near the front end 51e of the first reflector 51 and the projection lens 60, and the vicinity of the front end 51e is, for example, a position where the distance to the front end 51e is 10 mm or less. The focal point 60f may be located at the front end 51e or may overlap with the first reflector 51. Examples of materials that make up the projection lens 60 include resin and glass.
[0048] As shown in Figures 1 to 3, the holder 70 of this embodiment consists of a cylindrical support portion 71 extending in the front-rear direction and a pair of feet 72 extending rearward from both the left and right sides of the rear end of the support portion 71. A plurality of bases 73 projecting forward are provided at the front end of the support portion 71, and the flange portion 61 of the projection lens 60 is fixed to the bases 73 by means of ultrasonic welding or laser welding, for example. The feet 72 are fixed to the heat sink 20 by screws 81, and the projection lens 60 is fixed to the heat sink 20 via the holder 70. As a material for constituting the holder 70, for example, an opaque resin such as polycarbonate can be used, and in this embodiment, the support portion 71 and the feet 72 are integrally formed.
[0049] Next, we will describe the back side of heatsink 20.
[0050] Figure 10 is a rear view of the heat sink 20. The multiple heat dissipation fins 22 of the heat sink 20 are arranged in parallel with spacing between them and extend in the left-right direction. In Figure 10, for ease of viewing, only one reference numeral is used for each heat dissipation fin 22 and each gap 500 between adjacent heat dissipation fins 22. In Figure 10, the uppermost heat dissipation fin 22 is shown as heat dissipation fin 22a, and the lowermost heat dissipation fin 22b. Unless otherwise specified, heat dissipation fin 22 refers to heat dissipation fins 22a, 22b and the heat dissipation fins located between heat dissipation fins 22a, 22b.
[0051] The left and right sides of the heat dissipation fin 22 and the area above the heat dissipation fin 22a are surrounded by a peripheral wall portion 24. The peripheral wall portion 24 is a frame that surrounds the heat dissipation fin 22 as described above, and is separate from the heat dissipation fin 22. In the front-rear direction, the left and right walls of the peripheral wall portion 24 are shorter than the heat dissipation fin 22, and the upper wall is longer than the heat dissipation fin 22.
[0052] As shown in Figures 2, 3, and 10, a fan 30 is provided behind the multiple heat dissipation fins 22. The fan 30 mainly consists of an impeller 31 provided on the side opposite to the base plate 21 relative to the multiple heat dissipation fins 22, and a support unit 33. For ease of viewing, the impeller 31 is not shown in Figures 2 and 3. Figure 10 is also a view along the rotation axis R1 of the impeller 31. The impeller 31 and the support unit 33 are each made of, for example, resin.
[0053] The impeller 31 rotates around a rotation axis R1 that is perpendicular to the back surface of the base plate 21. The impeller 31 also rotates along the back surface of the base plate 21 to blow air into the gaps 500 between adjacent heat dissipation fins 22. In this embodiment, the impeller 31 rotates counterclockwise. The impeller 31 is rotatably supported by a support unit 33.
[0054] The support unit 33 mainly comprises a base member 33a on which the impeller 31 is arranged, and a support member 33b provided to the side of the impeller 31 and the base member 33a when the fan 30 is viewed from the rear.
[0055] The base member 33a is a circular plate-like member positioned in front of the impeller 31. For clarity, the base member 33a is not shown in Figure 10. The base member 33a is connected to the support member 33b via spokes 33c that are connected to the outer circumferential surface of the base member 33a and the inner circumferential surface of the support member 33b. Therefore, the support member 33b rotatably supports the impeller 31 via the base member 33a and the spokes 33c. For clarity, the spokes 33c are not shown in Figure 10.
[0056] The support member 33b is an outer frame that surrounds the sides of the impeller 31 and the base member 33a, and is formed in a generally square shape. In this embodiment, two generally parallel sides of the generally square support member 33b are aligned in the left-right direction. The support member 33b is shorter than the heat dissipation fins 22 in the left-right direction and longer than the distance between the heat dissipation fins 22a and 22b in the up-down direction. The front surfaces of the base member 33a and the support member 33b are in contact with the rear ends of the heat dissipation fins 22, but may be separated from the rear ends. The four corners of the support member 33b are rounded.
[0057] Through holes 33d are provided in the upper right and lower left corners of the support member 33b, and screws 501 are inserted into the through holes 33d, which are then screwed into the mounting bosses 23a and 23b. In this way, the fan 30 is attached to the heatsink 20 via the support member 33b and the mounting bosses 23a and 23b.
[0058] Next, the positions of the mounting bosses 23a and 23b will be explained using Figure 10. In Figure 10, the mounting bosses 23a and 23b are hidden by the fan 30 and are not visible, but they are shown with dashed lines for easier understanding.
[0059] In Figure 10, a straight line passing through the rotation axis R1 and extending in the direction of the heat dissipation fin 22 is shown as the first reference line 503a, and a straight line passing through the rotation axis R1 and extending perpendicular to the first reference line 503a is shown as the second reference line 503b. Four regions are formed by the reference lines 503a and 503b, and the upper right, upper left, lower left, and lower right regions with respect to the rotation axis R1 are shown as regions 510a, 510b, 510c, and 510d, respectively. For ease of viewing, each region is shown slightly offset from the reference lines 503a and 503b. When viewing the fan 30 from the rear, regions 510a and 510b, and regions 510c and 510d are adjacent regions in the direction of the heat dissipation fin 22. Furthermore, since the impeller 31 rotates counterclockwise, region 510a in regions 510a and 510b, and region 510c in regions 510c and 510d, are the regions on the rear side in the direction of rotation of the impeller 31. In the heat sink 20, the mounting boss 23a is provided in the rear region 510a, and the mounting boss 23b is provided in the rear region 510c. Therefore, the mounting bosses 23a and 23b are provided in the rear regions 510a and 510c, respectively. Note that it is sufficient that at least a part of the mounting boss 23a is provided in the rear region 510a, and at least a part of the mounting boss 23b is provided in the rear region 510c.
[0060] As described above, the support member 33b is attached to the mounting bosses 23a and 23b. Therefore, when viewing the fan 30 from the rear, the mounting bosses 23a and 23b are located to the sides of the impeller 31. Furthermore, since through holes 33d are provided in the upper right and lower left corners of the support member 33b, an example is shown where the mounting boss 23a overlaps the upper right corner and the mounting boss 23b overlaps the lower left corner. The mounting boss 23a is located between the first reference line 503a and the heat dissipation fin 22a furthest upward from the first reference line 503a, specifically in the gap 500 between the heat dissipation fin 22a and the heat dissipation fin 22 adjacent to it. The mounting boss 23b is located on the outside of the heat dissipation fin 22b on the opposite side of the gap 500. The mounting bosses 23a and 23b, positioned as described above, do not overlap each other along the extending direction of the heat dissipation fin 22. Mounting boss 23a is connected to heat sink fin 22a and heat sink fin 22 adjacent to heat sink fin 22a, and mounting boss 23b is connected to heat sink fin 22b. Note that mounting bosses 23a and 23b may be connected to at least one of the adjacent heat sink fins 22 that form a gap 500, or they may be separated from the heat sink fins 22.
[0061] In Figure 10, between the first reference line 503a and the heat dissipation fin 22a furthest upward from the first reference line 503a, the region that overlaps with the region 510b on the front side in the direction of rotation of the impeller 31 in the direction of extension of the heat dissipation fin 22, in the direction of extension of the heat dissipation fin 22, is shown as a predetermined region 520a. When the fan 30 is viewed from the rear, some of the LEDs of the first light source 41 overlap with the predetermined region 520a. At least one LED of the first light source 41 may overlap with at least a portion of the predetermined region 520a. Most of the air flowing through the gap 500 flows toward the edge of the gap 500 that overlaps with the region 510b described above, due to the influence of airflow vortices caused by the rotation of the impeller 31. For this reason, the predetermined region 520a is cooled more easily than the region outside the predetermined region 520a, and the heat generated by the first light source 41 that overlaps with the predetermined region 520a is easily transferred to the heat dissipation fin 22. In the above explanation, a predetermined region 520a was used, but even if the first light source 41 overlaps the predetermined region 520b as described above, the heat generated by the first light source 41 is easily transferred to the heat dissipation fin 22. The predetermined region 520b is the region between the first reference line 503a and the heat dissipation fin 22b that is furthest downward from the first reference line 503a, and it overlaps with the region 510d on the front side in the direction of rotation of the impeller 31 between adjacent regions 510c and 510d in the direction of extension of the heat dissipation fin 22. The first light source 41 may overlap both the predetermined regions 520a and 520b. In the above explanation, a first light source 41 was used, but the second light source 42 may overlap the predetermined regions 520a and 520b in the same way as the first light source 41.
[0062] Incidentally, structures 600 other than the heatsink 20 and fan 30 are arranged on the back side of the base plate 21. Structure 600 includes a conductive member 601 that supplies power to the fan 30, and the conductive member 601 includes power supply side wiring 605 including a connector 603.
[0063] The fan-side connector 35a of the fan-side wiring 35 extending from the fan 30 is connected to the connector 603. The connector 603 is also fixed to the back surface of the base plate 21 between the left wall of the peripheral wall portion 24 and the heat dissipation fin 22.
[0064] A portion of the power supply wiring 605 is supported by a clamp 630. The clamp 630 includes a holding portion 631 and a hooking portion 633. The holding portion 631 is generally concave when viewed from the rear of the fan 30 and is connected to the hooking portion 633. The hooking portion 633 hooks onto the receiving member 22c by sandwiching the left and right surfaces of the receiving member 22c located in region 510d. The receiving member 22c is a plate-shaped member and is provided on the back surface of the base plate 21. The receiving member 22c is connected to the side of the heat dissipation fin 22b opposite to the gap 500 side. The receiving member 22c may also dissipate heat as a heat dissipation fin. The power supply wiring 605 passes through the holding portion 631 in the front-to-back direction and hooks onto the holding portion 631, thereby holding the power supply wiring 605. The power supply wiring 605 extends further rearward from the holding part 631 and is connected to a power supply unit (not shown). When the power supply unit supplies power to the fan 30 via the power supply wiring 605 and the fan wiring 35, the fan 30 rotates.
[0065] Next, the location of structure 600 will be explained. Structure 600 is located in areas 710c and 710d, excluding areas 710a and 710b, which are downwind areas of the air that passes through the gap 500 in the direction of the extension of the heat dissipation fins 22 when the fan 30 is viewed from the rear. In Figure 10, for ease of viewing, areas 710a, 710b, 710c, and 710d are shown slightly shifted from the other areas mentioned above. Areas 710a, 710b, 710c, and 710d will be explained below.
[0066] Region 710a is located above the first reference line 503a in region 510b and is the region to the left of the gap 500 between adjacent heat dissipation fins 22 and to the left of the heat dissipation fins 22. Region 710b in this embodiment is located below the first reference line 503a in region 510d and is the region to the right of the gap 500 between adjacent heat dissipation fins 22 and to the right of the heat dissipation fins 22.
[0067] Regions 710c and 710d are areas on the back side of the base plate 21 that are outside the area enclosed by the heat dissipation fins 22a and 22b, excluding regions 710a and 710b. Region 710c is the area provided above the straight line parallel to the first reference line 503a and passing through the heat dissipation fins 22a, and above region 710b. Region 710d is the area provided below the straight line parallel to the first reference line 503a and passing through the heat dissipation fins 22b, and below region 710a.
[0068] Figure 10 shows an example where the conductive member 601 and clamp 630 are located in region 710d, not in regions 710a and 710b, and are positioned so as not to overlap with the air outlets for the air flowing along the heat dissipation fins 22. The conductive member 601 and clamp 630 may also be located in region 710c. In the front-rear direction, the conductive member 601 and clamp 630 are positioned lower than the rear end of the heat dissipation fins 22. The conductive member 601 is positioned away from the heat dissipation fins 22.
[0069] Next, we will explain the airflow on the heat dissipation fins 22 when the fan 30 is driven.
[0070] When the impeller 31 blows air into the gap 500 between adjacent heat dissipation fins 22, the air hits the back surface of the base plate 21 and flows through the gap 500 along the heat dissipation fins 22. Most of the air flowing through the gap 500 tends to flow towards the edge of the gap 500 due to the influence of airflow vortices caused by the rotation of the impeller 31. This edge overlaps with the front regions 510b and 510d.
[0071] Mounting bosses 23a and 23b are located on the side of the impeller 31 in the rear region 510a and 510c in the direction of rotation of the impeller 31. In the gap 500 where mounting boss 23a is located, the wind flows in the opposite direction from mounting boss 23a. Therefore, mounting boss 23a is positioned outside the path of the wind flowing through the gap 500, so as not to obstruct the wind. As a result, wind obstruction by mounting boss 23a is suppressed, and the wind flowing through the gap 500 where mounting boss 23a is located passes through the gap 500 and is blown out to the left side of the heat dissipation fin 22. Also, outside the heat dissipation fin 22b, the wind flows in the opposite direction from mounting boss 23b. As a result, wind obstruction by mounting boss 23b is also suppressed.
[0072] When viewing the fan 30 from the rear, in gaps 500 other than the gap 500 where the mounting boss 23a is located, air tends to blow out to the left of the heat dissipation fins 22 in gaps 500 above the first reference line 503a. Also, in gaps 500 below the first reference line 503a, air tends to blow out to the right of the heat dissipation fins 22.
[0073] The conductive member 601 and the clamp 630 are located in region 710d other than the downwind regions 710a and 710b of the air that passes through the gap 500 in the direction of extension of the heat dissipation fins 22. Therefore, the conductive member 601 and the clamp 630 are installed outside the path of the air that passes through the gap 500 and are positioned so as not to obstruct the air. As a result, the air is blown out to the side of the heat dissipation fins 22 with the obstruction of the air by these components suppressed.
[0074] Next, the formation of the low beam light distribution pattern by the vehicle headlight 1 will be explained. Figure 11 is an enlarged portion of Figure 4 and schematically shows examples of the optical paths of the light emitted from the first light source 41 and the light emitted from the second light source 42. Note that the reflection angle and refraction angle of the light shown in Figure 11 may not be accurate.
[0075] When forming the low beam light distribution pattern, light is emitted from the first light source 41. A portion of the light L1a emitted from the first light source 41 passes between the upper reflective surface 51ur of the first reflector 51 and one of the second reflectors 52a and is directly incident on the projection lens 60. Another portion of the light L1b emitted from the first light source 41 is reflected toward the projection lens 60 at the portion of the upper reflective surface 51ur of the first reflector 51 that includes the front end, and is incident on the projection lens 60. Yet another portion of the light L1c emitted from the first light source 41 is reflected by the reflective surface 52ar of one of the second reflectors 52a, is reflected toward the projection lens 60 at the portion of the upper reflective surface 51ur of the first reflector 51 that includes the front end, and is incident on the projection lens 60. As described above, the front end 51e of the first reflector 51 has a shape that matches the cutoff line, so that the light emitted from the first light source 41 that passes near the front end 51e of the first reflector 51 forms the cutoff line in the low beam light distribution pattern. Although not shown in the illustrations, a portion of the light emitted from the first light source 41 that diffuses in the left-right direction is reflected by the pair of upper side reflectors 53a and 53b and incident on the projection lens 60. In this way, the low beam light distribution pattern is formed by the light emitted from the first light source 41 that directly incident on the projection lens 60 and the light emitted from the first light source 41 that is reflected by the reflector unit 50 and incident on the projection lens 60. Light having this low beam light distribution pattern passes through the projection lens 60 and is emitted from the vehicle headlight 1 via the front cover 12. As described above, since the rear focal point 60f of the projection lens 60 is located near the front end 51e, the light distribution pattern of the low beam projected in front of the vehicle is a light distribution pattern that is inverted by the projection lens 60.
[0076] In this embodiment, the light L1a that directly enters the projection lens 60 is mainly light emitted in a direction parallel to the perpendicular line 41L. The light L1b that is reflected by the first reflector 51 and enters the projection lens 60, and the light L1c that is reflected by the second reflector 52a and then reflected by the first reflector 51 and enters the projection lens 60, are mainly light emitted in a direction not parallel to the perpendicular line 41L. However, the light L1a may include light emitted in a direction not parallel to the perpendicular line 41L, and the light L1c may include light emitted in a direction parallel to the perpendicular line 41L.
[0077] Figure 12 shows the light distribution pattern of the low beam in this embodiment. In Figure 12, S represents a horizontal line, V represents a vertical line passing through the center of the vehicle in the left-right direction, and the light distribution pattern PL of the low beam projected onto a virtual vertical screen positioned 25 m in front of the vehicle is shown by a thick line. The reflector unit 50 is shaped such that the light distribution pattern of the light from the first light source 41 incident on the projection lens 60 becomes this low beam light distribution pattern PL. The cutoff line CL of the low beam light distribution pattern PL corresponds to the shape of the front end 51e of the first reflector 51, and in this embodiment, it has a step.
[0078] Next, we will explain how the high beam light distribution pattern is formed by the vehicle headlight 1.
[0079] When forming the high beam light distribution pattern, light is emitted from both the first light source 41 and the second light source 42. As a result, as described above, the light from the first light source 41 forms the low beam light distribution pattern PL, and light having the low beam light distribution pattern PL is emitted from the vehicle headlight 1. A portion of the light L2a emitted from the second light source 42 passes between the lower reflective surface 51dr of the first reflector 51 and the other second reflector 52b and directly enters the projection lens 60. Another portion of the light L2b emitted from the second light source 42 is reflected toward the projection lens 60 at the portion of the lower reflective surface 51dr of the first reflector 51 that includes the front end, and enters the projection lens 60. Yet another portion of the light L2c emitted from the second light source 42 is reflected toward the projection lens 60 at the reflective surface 52br of the other second reflector 52b and enters the projection lens 60. Of the light emitted from the second light source 42, the light passing near the front end 51e of the first reflector 51 forms a cutoff line corresponding to the front end 51e in the light distribution pattern formed by the light emitted from the second light source 42. Although not shown in the illustrations, a portion of the light emitted from the second light source 42 that diffuses in the left-right direction is reflected by the pair of lower side reflectors 54a and 54b and incident on the projection lens 60. In this way, an additional light distribution pattern is formed by the light emitted from the second light source 42 that directly incident on the projection lens 60 and the light emitted from the second light source 42 that is reflected by the reflector unit 50 and incident on the projection lens 60. This additional light distribution pattern is a light distribution pattern that, when added to the low beam light distribution pattern PL, forms the high beam light distribution pattern. The light emitted from the second light source 42 that forms the additional light distribution pattern, together with the light emitted from the first light source 41, forms the high beam light distribution pattern. In this way, an additional light distribution pattern is formed by the light from the second light source 42, and the light having this additional light distribution pattern passes through the projection lens 60 and is emitted from the vehicle headlight 1 via the front cover 12. Therefore, light having the high beam light distribution pattern is emitted from the vehicle headlight 1. The additional light distribution pattern projected in front of the vehicle is a light distribution pattern that is inverted by the projection lens 60, similar to the low beam light distribution pattern PL.Furthermore, the cutoff line of the additional light distribution pattern is defined by the front end 51e of the first reflector 51, similar to the cutoff line CL of the low beam light distribution pattern PL. As a result, the cutoff line of the additional light distribution pattern and the cutoff line CL of the low beam light distribution pattern PL generally coincide, and the high beam light distribution pattern is a combination of the additional light distribution pattern and the low beam light distribution pattern PL.
[0080] In this embodiment, the upper side of the low beam light distribution pattern PL and the lower side of the additional light distribution pattern overlap, but the low beam light distribution pattern PL and the additional light distribution pattern do not have to overlap. In this case, at least a portion of the cutoff line of the additional light distribution pattern and at least a portion of the cutoff line CL of the low beam light distribution pattern PL coincide, and the additional light distribution pattern and the low beam light distribution pattern PL are connected. Also, in this embodiment, the light L2a that directly incident on the projection lens 60 is mainly light emitted in a direction parallel to the perpendicular line 42L. In addition, the light L2b that is reflected by the first reflector 51 and incident on the projection lens 60, and the light L2c that is reflected by the second reflector 52a and incident on the projection lens 60 are mainly light emitted in a direction not parallel to the perpendicular line 42L. However, the light L2a may include light emitted in a direction not parallel to the perpendicular line 42L, and the light L2b may include light emitted in a direction parallel to the perpendicular line 42L. Furthermore, in this embodiment, the integrated circuit 43 allows for individual adjustment of the power supplied to each LED of the second light source 42, thereby changing the additional light distribution pattern and thus the high beam light distribution pattern.
[0081] Figure 13 shows the light distribution pattern of the high beam in this embodiment, and is similar to Figure 12 in that it shows the light distribution pattern of the high beam. Note that the high beam light distribution pattern PH shown in Figure 13 is the case when light is emitted from all LEDs constituting the second light source 42. Also, in Figure 13, the cutoff line CL in the low beam light distribution pattern PL is shown by a dotted line. In the high beam light distribution pattern PH, the region below the cutoff line CL is mainly formed by light from the first light source 41, and the region above the cutoff line CL is mainly formed by light from the second light source 42.
[0082] As described above, in the lamp of this embodiment, at least a portion of the mounting boss 23a is provided in the rear region 510a.
[0083] The air sent from the impeller 31 to the gap 500 between adjacent heat dissipation fins 22 hits the back surface of the base plate 21 and flows through the gap 500 along the heat dissipation fins 22. When viewing the fan 30 from the rear, most of the air flowing through the gap 500 tends to flow towards one end of the gap 500 due to the influence of airflow vortices caused by the rotation of the impeller 31. However, in the above configuration, at least a portion of the mounting boss 23a is provided in the rear region 510a. Furthermore, since the support member 33b is attached to the mounting boss 23a, the mounting boss 23a is provided on the side of the impeller 31 in the rear region 510a when viewing the fan 30 from the rear, in a position that does not obstruct the airflow. When the mounting boss 23a is provided in this manner, it is less likely to obstruct the airflow compared to when the mounting boss 23a is provided in the front region 510b. Therefore, the airflow is easily directed outwards to the sides of the heat dissipation fins 22, making it easier to cool the heat dissipation fins 22. Consequently, with the above configuration, the heat generated by the first light source 41 and the second light source 42 can be easily transferred to the heat dissipation fins 22, improving the cooling efficiency of the first light source 41 and the second light source 42.
[0084] Furthermore, in the lighting fixture of this embodiment, the structure 600 is located in a region 710d other than the leeward region of the wind that passes through the gap 500 in the direction of extension of the heat dissipation fins 22.
[0085] The air blown from the fan 30 into the gap 500 between adjacent heat dissipation fins 22 hits the back surface of the base plate 21 and flows through the gap 500 along the heat dissipation fins 22. When viewing the fan 30 from the rear, most of the air flowing through the gap 500 tends to flow towards one end of the gap 500 due to the effect of airflow vortices caused by the rotation of the fan 30. In the above configuration, the structure 600 is located in region 710d. This makes it more difficult for the structure 600 to obstruct the air passing through the gap 500 compared to when the structure 600 is located in regions 710a and 710b downwind of the air passing through the gap 500. The air is more likely to blow out to the side of the heat dissipation fins 22, making it easier to cool the heat dissipation fins 22. Therefore, according to the above configuration, it is possible to easily transfer the heat generated by the first light source 41 and the second light source 42 to the heat dissipation fins 22, and improve the cooling efficiency of the first light source 41 and the second light source 42.
[0086] Furthermore, the structure 600 is positioned away from the heat dissipation fins 22.
[0087] With the above configuration, compared to the case where the structure 600 is placed in contact with the heat dissipation fins 22, heat from the heat dissipation fins 22 may be less likely to be transferred to the structure 600, and deformation of the structure 600 due to such heat may be suppressed. Note that the structure 600 does not necessarily have to be placed away from the heat dissipation fins 22.
[0088] The heatsink 20 further includes mounting bosses 23a, and the fan 30 includes an impeller 31 and a support member 33b. At least a portion of the mounting bosses 23a is provided in the rear region 510a.
[0089] In the above configuration, a support member 33b is attached to the mounting boss 23a. Therefore, when viewing the fan 30 from the rear, the mounting boss 23a is located to the side of the impeller 31 in the rear region 510a, in a position that does not obstruct the airflow. When the mounting boss 23a is located in this manner, it is less likely to obstruct the airflow compared to when it is located in the front region 510b. As a result, the airflow is more likely to flow and blow out to the side of the heat dissipation fins 22, making it easier to cool the heat dissipation fins 22. Consequently, the above configuration makes it easier to transfer the heat generated by the first light source 41 and the second light source 42 to the heat dissipation fins 22, thereby improving the cooling efficiency of the first light source 41 and the second light source 42. Note that at least a portion of the mounting boss 23a does not need to be located in the rear region 510a.
[0090] Furthermore, at least a portion of the mounting bosses 23a and 23b is provided in the rear regions 510a and 510c, respectively.
[0091] With the above configuration, since the fan 30 is attached to the heatsink 20 at two points, the vibration of the fan 30 due to the rotation of the impeller 31 can be suppressed compared to the case where it is attached to the heatsink 20 at one point. When the vibration of the fan 30 is suppressed, it becomes easier to direct the air from the impeller 31 into the gap 500, and the heat dissipation fins 22 can be cooled more easily compared to the case where the vibration of the fan 30 is not suppressed. Note that at least a portion of the mounting bosses 23a and 23b do not need to be provided in the rear areas 510a and 510c, respectively.
[0092] Furthermore, the mounting boss 23a does not overlap with the mounting boss 23b along the extending direction of the heat dissipation fin 22.
[0093] With the above configuration, compared to the case where the mounting boss 23a overlaps the mounting boss 23b in the extending direction, the airflow is more easily directed outwards to the sides of the heat dissipation fins 22, making it easier to cool the heat dissipation fins 22. Therefore, the heat generated by the first light source 41 and the second light source 42 can be more easily transferred to the heat dissipation fins 22, improving the cooling efficiency of the first light source 41 and the second light source 42.
[0094] Furthermore, the first light source 41 overlaps with at least a portion of the predetermined region 520a, and the predetermined region 520a overlaps with the front region 510b.
[0095] As described above, most of the air flowing through the gap 500 flows toward the edge of the gap 500 that overlaps with the region 510b on the front side in the direction of rotation of the impeller 31. For this reason, in the heat sink 20, the predetermined region 520a is cooled more easily than the region outside of the predetermined region 520a. With the above configuration, compared to the case where the first light source 41 and the second light source 42 overlap with the outer region, it is possible to more easily transfer the heat generated by the first light source 41 and the second light source 42 to the heat dissipation fins 22, thereby improving the cooling efficiency of the first light source 41 and the second light source 42. Note that the first light source 41 and the second light source 42 do not have to overlap with the predetermined region 520a, and the predetermined region 520a does not have to overlap with the front region 510b.
[0096] In this embodiment, in the arrangement of the fan 30 relative to the heat dissipation fins 22, two of the generally parallel sides of the generally square-shaped support member 33b are aligned in the left-right direction, and the remaining two parallel sides are aligned in the up-down direction. However, the arrangement of the fan 30 relative to the heat dissipation fins 22 is not limited to this. Figure 14 is a rear view of the heat sink 20 in a modified example. In Figure 14, some of the fan-side wiring 35 is omitted from the illustration.
[0097] In this modified example, the arrangement of the fan 30 relative to the heat dissipation fins 22 is such that the fan 30 is rotated 45 degrees clockwise around the rotation axis R1 compared to this embodiment.
[0098] In this modified example, the mounting bosses 23a and 23b are provided in the same gap 500. This gap 500 is, for example, the gap that coincides with the first reference line 503a when the fan 30 is viewed from the rear. Mounting boss 23a is provided to the right of mounting boss 23b and coincides with mounting boss 23b along the extending direction of the heat dissipation fin 22. In mounting boss 23a, a portion is provided in region 510a and the remaining portion is provided in region 510d. In mounting boss 23b, a portion is provided in region 510c and the remaining portion is provided in region 510b. Note that mounting boss 23a only needs to coincide with at least a portion of mounting boss 23b along the extending direction of the heat dissipation fin 22.
[0099] Although the present invention has been described above with reference to the above embodiments and modifications, the present invention is not limited thereto.
[0100] Either mounting boss 23a or 23b may be provided. Therefore, it is not necessary to provide multiple mounting bosses 23a, 23b and through holes 33d; one is sufficient.
[0101] According to the present invention, a lighting fixture is provided that can improve the cooling efficiency of the light source and can be used in fields such as automobiles.
Claims
1. A substrate on which the light source is mounted, A heat sink comprising a base plate on which the substrate is placed, a plurality of heat dissipation fins arranged in parallel at intervals from each other on the back surface of the base plate opposite to the substrate side, and mounting bosses provided on the back surface, A fan comprising: an impeller provided on the side of the plurality of heat dissipation fins opposite to the base plate, which rotates along the back surface to send air into the gaps between adjacent heat dissipation fins; and a support member provided on the side of the impeller, which supports the impeller and is attached to the mounting boss, Equipped with, At least a portion of the mounting boss is provided in the rearward region in the direction of rotation of the impeller, between adjacent regions in the direction of extension of the four regions formed by a first reference line extending through the rotation axis of the impeller and in the direction of extension of the heat dissipation fins, and a second reference line extending through the rotation axis and in a direction perpendicular to the first reference line, when the fan is viewed from the rear. A lighting fixture characterized by the following features.
2. A substrate on which the light source is mounted, A base plate on which the substrate is placed, and a heat sink including a plurality of heat dissipation fins arranged in parallel at intervals from each other on the back surface of the base plate opposite to the substrate side, A fan is provided on the side of the plurality of heat dissipation fins opposite to the base plate, and rotates along the back surface to blow air into the gaps between adjacent heat dissipation fins, Structures other than the heat sink and the fan, which are arranged on the back side of the base plate, Equipped with, The structure includes a conductive member that supplies power to the fan and is located in a region other than the leeward direction of the wind that passes through the gap in the direction in which the heat dissipation fins extend. A lighting fixture characterized by the following features.
3. The aforementioned structure is positioned away from the heat dissipation fins. The luminaire according to feature 2.
4. The light source overlaps with at least a portion of a predetermined region between a first reference line extending in the direction of extension through the rotation axis of the fan when the fan is viewed from the rear, and the heat dissipation fin that is furthest from the first reference line among the plurality of heat dissipation fins. The predetermined region overlaps with the region on the front side in the direction of rotation of the fan, among four regions formed by the first reference line and the second reference line extending in a direction perpendicular to the first reference line through the rotation axis, where adjacent regions in the extending direction are located. The luminaire according to feature 2 or 3.
5. The heat sink further includes mounting bosses provided on the back surface, The fan includes an impeller and a support member provided to the side of the impeller, supporting the impeller and attached to the mounting boss. At least a portion of the mounting boss is provided in the rearward region in the direction of rotation of the impeller, between adjacent regions in the direction of rotation of the impeller, which are formed by a first reference line extending in the direction of extension through the rotation axis of the impeller and a second reference line extending in a direction perpendicular to the first reference line and through the rotation axis, when the fan is viewed from the rear. The luminaire according to feature 2.
6. At least a portion of the mounting boss is provided in each of the rear regions of the impeller in the direction of rotation between adjacent regions in the extending direction of the four regions. A luminaire according to feature 1 or 5.
7. One of the mounting bosses does not overlap the other mounting boss along the extending direction. The luminaire described in feature 6.
8. One of the mounting bosses overlaps with at least a portion of the other mounting boss along the extending direction. The luminaire described in feature 6.
9. When the fan is viewed from the rear, the light source overlaps with at least a portion of a predetermined area between the first reference line and the heat dissipation fin that is furthest from the first reference line among the plurality of heat dissipation fins. The predetermined region overlaps with the region on the front side in the rotational direction of the impeller between adjacent regions in the extending direction. A luminaire according to feature 1 or 5.